Unlike the broadcast and telecom markets, the professional audiovisual industry has been slow to adopt optical fiber signal distribution. Indeed, the majority of displays, projectors, and interface products seen at the recent InfoComm show in Anaheim still depend heavily on multi-wire analog video cables and universal twisted pair (UTP) Cat5 wiring to move signals around.

The fact that fiber optic cables and connectors have come way down in price hasn’t been followed by a corresponding increase in demand for them. Yet it was clear from InfoComm that there is increasing demand for ultra high-resolution widescreen displays, HD video servers, high-definition videoconferencing, and a host of other bandwidth-hungry products that would be best served by modulated beams of light.

One possible objection to the use of fiber optic cables could be preparing and installing the connectors; a process that is a lot simpler than it was a decade ago but still deters many AV systems integrators.

RGB Spectrum came up with a novel solution to that problem at InfoComm with their XtendView line of DVI fiber optic cables. These hybrid cables utilize a one-piece DVI-to-fiber adapter plug at each end, and employ multimode fiber to carry red, green, blue, and sync signals. A DDC signal and +5VDC are carried over conventional copper wire that travels alongside the fiber.

According to RGB Spectrum, the cables are available in four lengths (5, 10, 15 and 30 meters), support resolutions to 1920×1080, and are fully compliant with the DVI 1.0 standard. A companion switcher, the Linx DVI 8×8, has been designed by RGB Spectrum to work with these new cables.

In a way, XtendView is just another hybrid signal distribution system like Cat5. And yes, there were several companies at InfoComm showing DVI and HDMI signal transport over Cat5 interfaces.

The difference? UTP/Cat5 is an RF-modulated system that is, by design, bandwidth-limited to several hundred megahertz (MHz), while XtendView’s optical fiber paths provide hundreds of gigahertz (GHz) of bandwidth. Not only that, fiber signal paths have high immunity to impulse noise and strong adjacent RF and AC fields, both of which can bedevil UTP receivers.

RGB Spectrum’s 8×8 DVI switcher and fiber/copper "solution" are clever products and will probably have the greatest appeal for staging and rental companies, who have to deal on a regular basis with complex, temporary AV installations in less-than-optimal video and audio signal transmission environments like convention centers and hotel ballrooms. (Can you say hum bars?)